Geophone cable



July 8, 1958 K. w. MCLOAD 2,842,751

GEOPHONE CABLE Filed March 22, 1957 /(e/7/7e//7 l V. M 1000 3 INVENTOR.

ATTORA/EKS United States Patent GEOPHONE CABLE Kenneth W. McLoad, Houston, Tex., assignor to Vector Manufacturing Company, Houston, Tex., a partnership Application March 22, 1957, Serial No. 647,852

6 Claims. (Cl. 339151) This invention relates to a geophone cable for connecting one or more geophones to a recording apparatus and more particularly to a cable take-out to which a geophone lead may be connected.

This invention is an improvement in the general type of take-out shown in the application of Cifton O. Randall and Lawrence D. Zepernick, Serial No. 402,298, in particular, and in any take-out employing a spring type terminal in general.

The take-out and clip shown in said Randall et al. application has been extensively used and has proved successful. On occasions, however, a truck driven over the clip will cause the take-out to be distorted to an oval shape.

By this invention there is provided a take-out which retains the advantages of the contractible-expansible terminal such as the sinusoidal wire of the Randall et al. application and which will withstand much higher crushing forces. The take-out of this invention has been subjected to load up to 750 lbs. per square inch without objectionable deformation. This is as great a loading as will normally be encountered in the field. Deformation was less than 0.10 inch.

it is an object of this invention to provide a take-out of the type referred to above which will withstand large crushing loads without objectionable deformation.

Another object is to strengthen the take-out of the type referred to above against deformation without impairing the free bending, stretching and contracting action of the terminal.

Another object is to strengthen a take-out as in the preceding object with a rigid piece of metal in which the arrangement is such that the rigid piece of metal does not cause localized fatigue and failure of the wires of the cable.

Another object is to strengthen a take-out of the type referred to above and to provide additional bearing area for clips when the terminals are worn down to avoid rapid wearing away of the terminal by clips not designed to be used with the take-out.

Other objects, features and advantages of this invention will be apparent from the specification, claims and drawings.

In the drawings wherein there is shown an illustrative embodiment of this invention and wherein like reference numerals indicate like parts:

Fig. 1 is a side view of a take-out constructed in accordance with this invention;

Fig. 2 is an exploded schematic view of a section of a geophone cable and the terminals and supporting arcs with loops of a pair of wires lifted out from the cable preparatory to being secured to the terminals; and

Fig. 3 is a schematic view of a partially assembled cable take-out illustrating the assembly of the take-out just before the boot of insulating material is applied to the take-out.

The cable, terminals, and manner of connecting the terminals to the wires lifted out of the cable and the 2,842,751 Patented July 8, 1958 boot of insulating material overlying the terminals provided by the springs are generally the same as those in said Randall et al. application and for a detailed discussion of these parts, their assembly and function, reference is specifically made to the Randall et al. application.

In general, a plurality of individually insulated wires 11 are confined within a sheathing of flexible material 11. At spaced points along the cable where it is desired to connect a geophone to the cable, the sheathing is split as at 12 and loops 13 and 14 which were provided in the bundle of wires as it passed through the sheathing extruder are lifted out and skinned. These loops are secured to the individual electrical terminals 15 and 16, these terminals being provided on opposite sides of the take-out.

It has been found that the take-out illustrated in the Randall et al. application will tend to flatten out and the terminals will take substantially the shape shown in the drawing of this application. Therefore, it is preferred to form the terminals 15 and 16 in the shape which they would'assume if distorted under a heavy load.

In order to electrically insulate the two terminals from each other, cylindrical flexible members 17 and 18 of insulating material are placed along opposite sides of the cable and between the two terminals.

The terminals may be temporarily secured in place on the cable by string ties 18 which tie the terminals to each other at each of the cylindrical insulators.

Preferably, the connection between one of the lifted loops 14 and a terminal is made by a third wire 19 wrapped around both the lifted out loop and terminal. After this connection has been made and the terminals secured in place, the connection between the lifted out wire and terminal may be taped as at 21.

In order to support the terminal against deformation, a support 22 of rigid material is placed between the sheathing of the cable and each terminal. This support 22 is preferably arced to conform to the outer periphery of the cable.

As the wires which form terminals 15 and 16 have portions which extend transversely of the lengthwise dimension of the cable, the supports are preferably provided with corrugations 23 which also extend transversely to the cable and receive the transverse portions of the terminals. This feature serves to lock the supports against movement lengthwise of the cable and also provides an additional bearing area for clips once the wires forming the terminals have been worn down.

It has been found that when clips other than those designedfor use with the spring type of take-out are used there is a rapid wearing away of the cable take-out terminal. By using the support of this invention, an additional bearing area may be provided for the clips once the terminals have been worn down a predetermined amount and this additional bearing area will tremendously increase the life of the take-out.

The support may extent transversely of the take-out to the cylindrical insulators 17. Preferably, it is provided with a flange section 24 which extends outwardly in a position to strike the insulators 1'7 and prevent turning movement of the supports around the cable without also carrying the insulators 17.

The dimension of these supports lengthwise of the cable should be suflicient to provide the desired support of the terminals but not sufficient to cause localized bending of the several wires 10 at the edges of the supports. In other words, the length of the supports should be less than the normal bending arc of the cable so that the cable may bend freely without bending about the edges of the supports. In practice, it has been found that the supports may have a length which approximates the width of the larger window 25 cut in the boot 26 to expose the terminal 16. It is preferred that the support be slightly larger in size than this window so that the boot of flexible material 26 when applied over the take-out will cover the edges of the support 22 and tend to hold it in position. This distance is sufliciently small that there will be little or no tendency for localized bending of the individual wires about the edges of the support. While it is preferred that the supports extend completely across the windows 25 and 27, it will be appreciated that they may extend some lesser distance and some degree of support for the terminals will be present. However, as the size of the support decreases, the amount of support correspondingly decreases.

The boot 26 is preferably molded about the terminals and bonds with the cable sheathing and the insulating cylinders 17. In this manner the terminals and support are bonded in place on the exterior of the cable. However, the terminals and 16 are still free to bend and to expand or contract as the take-out is bent. The supports will not interfere with this action in any appreciable amount and the features of the flexible, expansible, contractible terminal will be retained while at the same time the support 22 will support the take-out against deformation. It will be appreciated that the strength of this support will depend upon the metal from which it is constructed and the shape and size of the corrugations 23 which tend to strengthen the arc.

It will be appreciated that while the terminals 15 and 16 are in the form of sinusoidally arranged wires with the axis of the sinusoid extending lengthwise of the cable, other flexible, contractible and expansible terminals or wires differently formed could be utilized with this invention.

While the take-out illustrated employs opposed terminals for attachment to two separate wires within the cable and the windows 25 and 27 are of different widths to polarize the clip to be used therewith, it will be understood that this invention will work equally well in protecting a take-out having a single terminal.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

l. A geophone cable comprising, a plurality of separately insulated wires in a common sheathing; flexible, expansible, and contractible terminal means extending along and overlying the sheathing; means electrically connecting the terminal means to one of the insulated wires; a boot of flexible insulating material overlying the terminal means; a window in the boot exposing a portion of the terminal means; and a rigid support between the sheathing and terminal means; said support underlying the window and supporting the exposed portion of the terminal means.

2. The cable of claim 1 wherein the terminal means is an sinusoidally arranged wire with the axis of the sinusoid extending lengthwise of the cable.

3. A geophone cable comprising, a plurality of separately insulated wires in a common sheathing, a wire extending along and overlying the sheathing to provide a terminal, said wire having portions extending transversely of the cable to provide for expansion and contraction of the terminal, means electrically connecting the terminal means to one of the insulated wires, a boot of flexible insulating material overlying the terminal means, a window in the boot exposing a portion of the terminal means, and a rigid support between the sheathing and terminal, said support underlying the window and having corrugations extending parallel to and receiving the transversely extending portions of the wire to support the wire and lock the support against movement lengthwise of the cable.

4. The cable of claim 3 wherein the support is arced to conform to the contour of the sheathing and the corrugations strengthen the are.

5. A geophone cable comprising, a plurality of separately insulated wires in a common sheathing, first and second wires extending along and overlying opposite sides of the sheathing to provide terminals, each wire having portions extending transversely of the cable to provide for expansion and contraction of the terminals, means insulating the terminals from each other, means electrically connecting the terminals to insulated wires in the cable, a boot of flexible insulating material overlying the terminals, opposed windows in the boot exposing portions of the terminals, and a rigid arced support between each terminal and the sheathing, said supports underlying the windows and having corrugations extending across the arc and receiving the transversely extending portions of the wires to support the wires and lock the supports against movement lengthwise of the cable.

6. A geophone cable comprising, a plurality of separately insulated wires in a common sheathing, first and second wires extending along and overlying opposite sides of the sheathing to provide terminals, each wire having portions extending transversely of the cable to provide for expansion and contraction of the terminals, means insulating the terminals from each other, means electrically connecting the terminals to insulated wires in the cable, a boot of flexible insulating material overlying the terminals, opposed Windows in the boot exposing portions of the terminals, and a rigid arced support between each terminal and the sheathing of a dimension lengthwise of the cable not substantially greater than the like dimension of the windows, said supports underlying the windows and having corrugations extending across the arc and receiving the transversely extending portions of the wires to support the wires and lock the supports against movement lengthwise of the cable.

Winterhalter Aug. 26, 1941 Ramdell et a1. July 10, 1956 

